I played with a C&W/Americana band which insisted on playing the songs in the key the recording SEEMED to be in - which led to some very strange capo usage as one would capo to play the (say) D in open A style while the other would capo to play the F in open G style.
Also, I say SEEMED as they didn't take into consideration the fact that many of the groups in question downtuned - usually by a semitone (half-step in Septic-speak) -but sometimes more, leading to our lot playing some very tortured chords & keys, while the originals were probably done using easy chords like A or G & just downtuning to fit their voices.
I wouldn't have minded, but on more than one occasion, they decided to change key between practices & when the key was called on stage, it turned out they didn't know what key it actually was & were playing in a different key to what they thought, while I ended up in the key called & sounded (& was) totally wrong.
Didn't stay long with them.
I agree with most of the above.
There are singers with different ranges. Sometimes if you want that singer to sing a particular song, you just have to change the key to suit his/her range. I've done that quite a lot. The key(!) to doing this on bass it to see the bassline more as a visual pattern that can be moved up or down the neck. This is where playing *across* the neck on a 5 string can help.
Also, as has been mentioned, there are some chord shapes that must be used to make a song sound 'right' & if you shift key, you'll need to capo to achieve this.
IMO anything else is lazyness (ducks & runs.......)
G.